Medication Basics

Generic Name: Diltiazem

Brand Name: Cardizem, Cardizem CD, Cardizem LA, Cartia XT, Tiazac, Diltia XT
Medication Class: Calcium Channel Blocker

Description

Diltiazem, along with verapamil, are first generation calcium channel blockers which have mixed effects on both the heart and on constriction of blood vessels. This tends to make them less preferred as blood pressure medications due to increased side effects when compared to newer calcium channel blockers, such as amlodipine. However, due to these mixed effects, they are able to lower and control heart rate effectively; this is their primary use in modern medicine. Diltiazem is generally preferred over verapamil due to fewer side effects, but both medications affect heart contraction which may limit their use in a patient with chronic or congestive heart failure.

When might my doctor prescribe this medication?

Heart-rhythm disturbances (or arrhythmias) to control fast heart rate (primarily atrial fibrillation or atrial flutter)
High blood pressure (or hypertension)
Chest pain (or angina)
High lung pressures (or pulmonary hypertension)

I should NOT take this medication if:

I have had allergic reactions to diltiazem in the past
I have problems with slow heart rate and do NOT have a pacemaker
I have very low blood pressure

Adverse Effects (common)

Leg swelling
Headache
Slow heart rate
Constipation
Dizziness

Common Adult Doses and Forms

Diltiazem (Cardizem): 30 mg to 120 mg four times daily
Diltiazem (all extended release formulations): 120 mg to 480 mg once daily

Dosage Forms:
Diltiazem (Cardizem) (tablet): 30 mg, 60 mg, 90 mg, 120 mg
Diltiazem XR/XT/CD (Cardizem CD, Cartia XT, Tiazac, Diltia XT) (capsule): 120 mg, 180 mg, 240 mg, 300 mg, 360 mg
Diltiazem LA (Cardizem LA) (tablet): 120 mg, 180 mg, 240 mg, 300 mg, 360 mg, 420 mg

How should I take this medication?

Extended release products should not be chewed or crushed. Capsules can be opened and swallowed whole with applesauce or yogurt; do not chew. Diltiazem can be taken with or without food.

Please note that the content on CardioSmart is a summary of the most generally pertinent information about this drug but does not cover every side effect or precaution. However, everyone is unique, and the extent to which the information applies specifically to you should be a key point of discussion between you and your cardiologist or health care provider. The ultimate judgment regarding your care must be made by you and your healthcare provider together, in light of circumstances specific to you as a patient.